Furnace



(No Model.)

3 Sheets-Sheet 1. W. S. STEVBNSON, C. V. ROBERTS 8v J. K. MQLAUGHLIN.

` AIR HEATING FURNAGB. No. 545,829.

Patented Sept. 3, 1895.

Wifi/:fesses Wim (No Model.) 3 Sheets-Sheet 2. W. S. STEVBNSON, C..V. ROBERTS & J. K. MGLAUGHLIN. AIR HEATING FURNAGE.

Patented -Sept. 3,1895.

Hei, 2.

(No Model.) 3 Sheets-Sheet 3.

W. S. STEVENSON, G. V. ROBERTS' & J. K. MGLAUGHLIN. AIR HEATING FURNAGB.

.Nm 545,829. 4 Patented Sept. 3,1895.

NrrE 'freres WALTER S. STEVENSON, CLARENCE V. ROBERTS, AND JOHN K. MCLAUGH- I QIN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNORS TO THE THOMAS ROBERTS STEVENSON COMPANY, OF SAME PLACE.

AIR-H EATING. FURNACE.

SPECIFICATION forming part of Letters Patent No. 545,829, dated September 3, 1 895.

Application ledFebruary ZI. 1895. Serial No. 539,253. (No model.)

To all whom it may concern:

Be it known that we, WALTER S. STEVEN- soN, CLARENCE V. RoBER'rs, and JOHN K. McLAUeHLIN, citizens of the United States, and residents of Philadelphia, Pennsylvania,

have invented certain Improvements in Air- Heating Furnaces, of which the following is a specification.

The objects of our invention are, first, to 1o provide for the convenient and economical formation of an air-supplying ring around the top of the fire-pot; second,'to so constructa furnace that it can be used either as a plain hot-air furnace or as a combined hot-air and l5 hot-water furnace; third, to insure the rapid discharge of the heated air from the upper portion of the furnace; fourth, to provide efficient means for checking the drat't when desired; fifth, to improve the construction of 2o the grate, and, sixth, to. prevent loosening of the joints of the casing bythe expansion and contraction of the fire-pot and the parts mounted thereon. These objects we attain in the manner hereinafter set forth, reference being had to the accompanying drawings, in

which- Figure l is a longitudinal vertical section of a heating-furnace constructed in accordance 4with our invention. Fig. 2 is a trans- 5o verse section ofthe same, illustrating the hotwater connection; and Fig. 3 is a sectional plan view on the line 3 3, Fig. 1.

A is the frontplate of the furnace, mounted upon the base-ring A and having the dam- -pered fire-doorA2, dampered air-inlets A3, and ash-pit door A4 with damper-plate A5. The feed-door frame A6 is independent ofthe front plate and is provided with dampered airinlet A7.

B is the outer sheet-iron casing of the stove, mounted upon rings B and surmounted by the dome B2, which has the usual hot-air-discharge necks, that portion of the casing which upon the lire-pot and contains the feed-neck a and the sido necks a', the feed-neck a carrying the feed-door frame AG and the side necks communicating with an annular drum G, surmounting the crab and consisting of the `inner and outer sheet-metal rings b o', carrying an annular cap h2, the rings b bf being mounted upon an annular ring b3, which is seated upon the top of the crab F; also seated upon said crab is a central cylindrical drum 6o G', consisting of an annular casing CZ with cap-plate d', the products of combustion thusl having free access to both the annular and cylindrical drums. Depending from the rear portion of the ring h3 is the discharge-neck 65 G2 with projecting elbow G3, upon which is mounted the smokepipe G4, the neck G2 also communicating through a pipe G5 with the dampered neck G6, leading to the ash-pit, so

as to provide for the escape of dust from the 7o latter.

I Allv the parts thus fardescribed are, with the exception of the independent feed-door plate A6 and dampered inlet A7, common to hot-air furnaces heretofore constructed; but around the lower portion of the crab F of our improved furnace is formed aribfof inverted- U shape, this rib resting upon the top of the fire-pot and upon a flange f projecting outwardly therefrom and forming an air-tight 8o joint with said tiangeby reason of packing f2, resting upon the flange and surrounding the rib. The ribf, in connection with the top of the tire-pot and its fiangef, thus forms an air-chamber g, surrounding the tire-pot, and this air-chamber communicates with the dampered air-inlet A7 through a passage g', formed in an extension f3 of the hollow ribjprojecting beneath the feed-inlet neck a of the crab. The inner leg of the rib f, which rests upon 9o the top of the fire-pot, is somewhat shorter than the outer leg, and has formed in its under edge a series 'of notches g2, so that the air entering the chamber g from the front of the furnace is distributed in anumber of tine jets into the products of combustion arising from the fuel in the fire-pot.

It is manifest that. the same result may be attained by notching the upper edge of the nre-pot instead of the inner leg of the rib, or roo by notching both parts. Hence our invention is not limited as to the location of these notches.

We are aware that the use of an air-supplying ring at the top of the lire-pot is very old, and hence we do not broadly claim the same, this part of our inven tion being restricted to the special construction of the fire-pot, whereby the air-supplying ring is formed and a gas tight joint between the tire-pot and rib is insured.

In two of the lateral discharge-necks a of` the crab are formed openings, through either of which may be passed a pipe 'L' for the introduction of water when the furnace is to be used as a combined hot-air and hot-water furnace, said pipe forming a coil t in the central cylindrical drum G and passing out through the cap d of said drum and through the dome B2. The pipe 'i is threaded for the reception of nuts f2, whereby it is secured to the outer casing of the neck a of the crab, the opening in the opposite neck being closed by means of a plug 3 and nut f4, so that the pipe t' may entereither on the right or left hand side of the furnace, as may be most convenient. j In the dome B2 of the furnace'is aframe m, in which is mounted a rotary fan m', having vanes so inclined that the rising of the heated air in the furnace will cause rotation of said fan in the direction of the arrow, Fig. l, such movement having the effect of throwing the heated air outward and upward, so as to direct it into and through the discharge-necks of the dome, and thus insure a more rapid circulation and discharge than usual. When the water-heating pipe t' is used, the fan may have a hollow hub through which said pipe can pass. The elbow G3 of the dischargeneck G2 is closed at the outer end by a swinging plate n, which can be raised or lowered soas to check the draft by permitting an inflow of air. It is advisable, however, t0 limit the area of discharge from the neck Gr2 simultaneously with the inlet of the external air, and for this reason We mount in the elbow G3 a damper n', which has a pivotrod provided with an arm n2, the latter being connected by a rod n3 to an arm on the checkplate n, so that as the latter is raised to permit an inflow of air the damper n will be simultaneously raised to limit the iow of the products of combustion from the neck G2, the joint operation effecting a rapid and positive checking of the draft to the desired extent.

The opening in the front plate A of'the'furnace is somewhat larger than the feed-neck which passes through the same and carries the feed-door frame. Hence.. said feed-,neck

and door-frame are free to rise and fall as the lire-pot expands and shrinksbecause of vchanging temperatures without correspond- `the dampered air inlet at the frontof the casing, with the tire pot and the crab sui-mounting the same, andhaving their meeting portions constructed so as to form an air chamber, surrounding the upper portion of the fire pot and discharging into the same, a portion of the crab extending to the dampered air inlet, substantially as specified.'

2. A heating furnace having a crab section with central drum, an annular drum surrounding the-same and lateral discharge necks for the escape of the products of combustion, and a water pipe coiled in the central drum, the supply pipe therefor passing through one of said discharge necks, substantially as specified. j

3. The combination of the internal combustion chamber casing and the outer hot a-ir casing of a heating furnace, said outer casing having lateral hot air discharge openings, with a rotary fan located in the upper portion of the hot air chamber between the combustion chamber casing and the hot air casing, whereby it is rotated by the rise of the heated air, and directs said heated air toward the lateral hot air outlets, substantially as specified.

4. The combination of the front plate and outer casing of the furnace, with the fire pot, the crab mounted thereon, and the feed door frame carried by said crab and free to move independently of the front plate, substantially as specified.

In testimony whereof we have signed our names to this specication in the presence of two subscribing witnesses.

WALTER S. STEVENSON. CLARENCE V. ROBERTS. JOHN K. MCLAUGHLIN.

fitnessesz FRANK E. BEoHroLD, JOSEPH H. KLEIN.

ICO 

